memcached-protocal 0.1.11

use std::io::BufRead;
use super::deletion_command::DeletionCommand;
use super::retrieval_command::RetrievalCommand;
use super::store_command::StoreCommand;

use ::error::Result;
use ::error::ErrorKind;
use ::byte_utils::peek_until;


#[derive(Debug, PartialEq)]
pub enum Command {
    Delete(DeletionCommand),
    Retrieval(RetrievalCommand),
    Store(StoreCommand),
}


pub fn parse<R: BufRead>(reader: &mut R) -> Result<Command> {
    use self::Command::*;

    let buf = try!(peek_until(reader, "\r\n"));
    let len = buf.len();
    let cmd_str = try!(String::from_utf8(buf));
    let segments = cmd_str.split_whitespace().collect::<Vec<&str>>();
    let length = segments.len();
    if length < 1 {
        reader.consume(len);
        return Err(ErrorKind::ClientError("wrong size of params".to_owned()).into());
    }
    let cmd = segments[0];
    Ok(match cmd {
        "set" | "add" | "replace" | "append" | "prepend" | "cas" => Store(try!(StoreCommand::parse(reader))),
        "get" | "gets" => Retrieval(try!(RetrievalCommand::parse(reader))),
        "delete" => Delete(try!(DeletionCommand::parse(reader))),
        _ => {
            reader.consume(len);
            return Err(ErrorKind::ClientError("not supported command".to_owned()).into())
        },
    })
}